Cuba and the United States will always have differences, Cuban President Raul Castro said during a historic visit by President Barack Obama, especially while the United States maintains a "double standard" on human rights.
"The two nations have profound differences that are never going to disappear," Mr Castro told reporters while standing alongside Mr Obama after they held talks at Cuban government headquarters.
Mr Obama said the two differed on democracy and human rights and that they had "frank and candid" discussions about it.
Mr Castro said they could achieve much greater cooperation if the United States lifted its 54-year-old trade embargo on the island.
The two leaders held face-to-face meetings a day after Mr Obama arrived for the first visit by a US president in almost 90 years, achieving a goal for his final year in office that became possible after secret talks led to a 2014 agreement to normalise relations between the two Cold War-era foes.
The opening ended decades of US efforts to force Cuba to change through isolation.
But Mr Obama is under pressure from critics at home to push Castro's Communist government to allow political dissent and to further open its Soviet-style economy.
Mr Obama said the embargo with Cuba is going to end but is not sure when, but said the path the US is on with Cuba will continue beyond his administration.
But he said disagreements over human rights and democracy is an impediment to strengthening ties.
In response, Mr Castro said "give me a list of political prisoners and I will free them" before the night is done.
Barack Obama has become the first US President to visit Cuba in almost 90 years https://t.co/HYsJd5j6dohttps://t.co/nbCCdrXGnh
— RTÉ News (@rtenews) March 21, 2016
Traveling with his family, Mr Obama was greeted by cheering crowds on the road from the airport and while on a walking tour of Old Havana yesterday.
Besides meeting Raul Castro, he also plans to visit a state-owned micro brewery and attend a state dinner.
Tomorrow, he will deliver a speech on live Cuban television and attend an exhibition game between Major League Baseball's Tampa Bay Rays and Cuba's national team.
White House pours cold water on Fidel meeting
The White House has all but ruled out a meeting between Mr Obama and veteran Cuban leader Fidel Castro during the trip.
A senior aide said that neither the administration nor the Cuba authorities had asked for a meeting between Mr Obama and the 89-year-old.
Mr Castro is rarely seen in public these days and when photographed in state-run media he has appeared in a wheel chair.
Mr Obama earlier suggested in a television interview with ABC that he may be open to a meeting.
"If his health was good enough that I could meet with him, I'd be happy to meet with him. Just as a symbol of the end of, or the closing of this Cold War chapter in our mutual histories."
